What is the equivalent of SQL “like” in MongoDB?

You can use “$regex” operator to implement the equivalent of SQL ‘like’ in MongoDB. To implement it, let us create a collection with a document. The query to create a collection with a document is as follows −

> db.sqlLikeDemo.insertOne({"UserName":"John Smith","UserAge":24}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c912e124afe5c1d2279d6a5") } > db.sqlLikeDemo.insertOne({"UserName":"John Doe","UserAge":21}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c912e264afe5c1d2279d6a6") } > db.sqlLikeDemo.insertOne({"UserName":"Chris Williams","UserAge":22}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c912e404afe5c1d2279d6a7") } > db.sqlLikeDemo.insertOne({"UserName":"Robert Taylor","UserAge":26}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c912e4d4afe5c1d2279d6a8") } > db.sqlLikeDemo.insertOne({"UserName":"John Brown","UserAge":27}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c912e6c4afe5c1d2279d6a9") } > db.sqlLikeDemo.insertOne({"UserName":"Mike Brown","UserAge":23}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c912e794afe5c1d2279d6aa") } > db.sqlLikeDemo.insertOne({"UserName":"Larry Smith","UserAge":24}); {    "acknowledged" : true,    "insertedId" : ObjectId("5c912e8c4afe5c1d2279d6ab") }

Display all documents from a collection with the help of find() method. The query is as follows −

> db.sqlLikeDemo.find().pretty();

The following is the output −

{    "_id" : ObjectId("5c912e124afe5c1d2279d6a5"),    "UserName" : "John Smith",    "UserAge" : 24 } {    "_id" : ObjectId("5c912e264afe5c1d2279d6a6"),    "UserName" : "John Doe",    "UserAge" : 21 } {    "_id" : ObjectId("5c912e404afe5c1d2279d6a7"),    "UserName" : "Chris Williams",    "UserAge" : 22 } {    "_id" : ObjectId("5c912e4d4afe5c1d2279d6a8"),    "UserName" : "Robert Taylor",    "UserAge" : 26 } {    "_id" : ObjectId("5c912e6c4afe5c1d2279d6a9"),    "UserName" : "John Brown",    "UserAge" : 27 } {    "_id" : ObjectId("5c912e794afe5c1d2279d6aa"),    "UserName" : "Mike Brown",    "UserAge" : 23 } {    "_id" : ObjectId("5c912e8c4afe5c1d2279d6ab"),    "UserName" : "Larry Smith",    "UserAge" : 24 }

Here is the query that works like SQL ‘like’ clause i.e. the record with “UserName” John −

> db.sqlLikeDemo.find({"UserName":{"$regex": "John"}}).pretty();

The following is the output −

{    "_id" : ObjectId("5c912e124afe5c1d2279d6a5"),    "UserName" : "John Smith",    "UserAge" : 24 } {    "_id" : ObjectId("5c912e264afe5c1d2279d6a6"),    "UserName" : "John Doe",    "UserAge" : 21 } {    "_id" : ObjectId("5c912e6c4afe5c1d2279d6a9"),    "UserName" : "John Brown",    "UserAge" : 27 }